This invention relates to an oil cooler for internal-combustion engines. More specifically, the invention relates to an oil cooler for installation between the engine and an oil filter and having at least one heat exchange space through which the oil flows that is to be cooled, and one heat exchange space through which the coolant flows, both spaces bordering on one another. In preferred contemplated embodiments, water serves as the coolant.
Oil coolers of this type are known in the form of disk coolers such as described in German Published Examined Patent Application (DE-AS) No. 28 43 432. In the case of these disk coolers, several hollow disks are arranged behind one another and in parallel to one another in a housing through which the cooling water flows, the oil flowing through said disks and the cooling water flowing around them. A disadvantage in the case of these disk coolers is the relatively expensive type of production requiring soldering and welding processes. Another disadvantage is the relatively heavy weight and the cooling performance that is not sufficient for some applications.
An oil cooler is known from German Patent (DE-PS) No. 19 34 193 where the hot oil coming from the internal-combustion engine is guided through a pipe coil arranged on the interior of a housing through which the water flows. However, this type of construction has the disadvantage of an expensive production because there also, the pipe coil must be attached by welding or soldering.
This invention is based on the objective of providing and oil cooler of the initially mentioned type that can be produced in a simpler way and without a soldering or welding process.
This objective is achieved by designing the heat exchange space through which the oil flows as a housing chamber into which a heat exchange body is inserted tightly. The coolant flows through the heat exchange body, which comprises a plurality of parallel pipes, the ends of which are held in respective bottom end walls of coolant collecting spaced disposed at opposite ends of the pipes. Such heat exchange bodies, which are known from water - air coolers with repect to their principles, can be inserted in a simple way into the housing chamber by means of sealing means or similar devices without any soldering or welding processes. For their production, they also do not require a soldering process. Another advantage is that the water flow is exactly defined by the parallel pipes, which is not ensured in the case of the known constructions.
The whole construction of the oil cooler may be designed according to the invention to be very simple when the coolant collecting spaces are formed by the two bottom end walls that are opposite one another and one fitted hood-shaped water box respectively. It is then possible to develop the housing chamber as a frame that is open at two sides in which the water boxes are inserted by sealing means and are in each case held by a flanged edge of the housing chamber. No soldering process is required for this purpose.
In a manner that is known per se, the pipes provided in the heat exchange body may be those having a circular-ring-shaped cross-section, the ends of which are sealed in the coolant space bottom end walls by expanding and/or by the insertion of sealing rings. The pipes, in turn are connected to form a pipe fin or rib block via a plurality of ribs or plates which extend essentially in planes located perpendicularly to the longitudinal direction of the pipes and are surrounded by flowing oil. The pipe rib block with the coolant space bottom end walls provided at both of its end sides, can be clamped tightly into the housing chamber before the two water boxes are fitted on. In this case, a surrounding sealing means is preferably provided between the coolant space bottom end walls and for the housing chamber. By the expanding of the pipe ends, the coolant space bottom end walls are pulled together and get jammed at the edge of the housing chamber.
In certain preferred embodiments, the housing chamber has a through-bore extending transversely to the pipes of the heat exchange body through which a hollow connecting piece can be guided in a simple way, the one end of which connecting piece can be screwed to the oil filter and the other to the engine. In this manner, the housing chamber can rest against the engine via a surrounding sealing means in which case oil inlet openings may be provided within the area of this sealing means, and the space closed off by the sealing means is connected to at least one connecting opening to the engine. As a result, the hot engine oil enters the housing chamber through the oil inlet openings, flows past the pipes through which the coolant, such as water, flows, and past the plates resting on them and advantageously, via a plurality of outlet openings, enters into an annulus of the filter. These outlet openings in turn lead into a space which is delimited with respect to the oil filter by a surrounding sealing means. The two spaces enclosed by the sealing means on both sides of the housing chamber may be formed respectively by one surrounding edge of the housing chamber at the front side of which the sealing means is arranged in each case.
In order to be able to arrange the connecting piece as well as the discharge piece for the coolant on the same side of the oil cooler for purposes of installation, one of the two water boxes is preferably provided with both connecting pieces and a separating wall between the inlet and the discharge piece, so that the coolant can flow only through one part of the pipes in one direction, and after the deflection in the other water box, then through the second part of the pipes back again into the first water box.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings(s) which show, for purposes of illustration only, an embodiment in accordance with the present invention.